The Cellular Level pt. 1
The cell membrane has selective permeability, what does this mean and which structure allows selective permeability?
only allows certain molecules to come in and out. The phospholipid bilayer allows for selective permeability
Which nitrogenous base is found in DNA, but not in RNA? What is it replaced with in RNA ?
thymine
replaced by uracil in RNA
What is happening to chromosomes during anaphase?
sister chromatids are being pulled towards opposite poles
What are the 3 embryonic germ layer, and what tissue type(s) are formed by each?
Ectoderm - nervous tissue + skin related epithelial tissue
mesoderm - muscle tissue + most connective tissue
Endoderm - epithelial linings of organ systems
What is the regeneration potential of nervous tissue and why?
Very poor regeneration potential - mature neurons do not divide.
There are 3 types of membrane proteins included in the cell membrane. Which type is only attached at the inner surface OR the outer surface, but does not poke out of both sides
peripheral membrane protein
in DNA replication, what is the purpose of helicase?
an enzyme that is used to 'unzip' the DNA strand at the replication fork
What are the 3 types of stem cells discussed in class and what can they become?
totipotent - can become anything in the body
pluripotent - can become anything except extraembryonic tissue
multipotent - can develop into limited cell types related to their tissue of origin
Which type of cell junction would be found in between cells of the heart for communication?
gap junctions
What are the three muscle types and what is the general structure of each
skeletal - striated, voluntary
Cardiac - striated, involuntary
smooth - non-striated, involuntary
The 'sugar coating' on the outside of the cell that gives the cell it's unique identity
What are Okazaki fragments?
Nucleotide bases must be added to the lagging strand in fragments because it is going in the 'incorrect' direction - these fragmented pieces are called Okazaki fragments
What signals the beginning of transcription? What signals the beginning of translation?
promotor region signals beginning of transcription
start codon signals the beginning of translation
Which of the 4 tissue types is the most abundant in the human body?
connective tissue
Which structure of a neuron receives signals for that neuron? which structure sends signals from that neuron?
axons send signals
The _______ gradient and the ________ gradient collectively make up the electrochemical gradient
concentration; electrical
What are the extra steps to process mRNA into mature mRNA in eukaryotes?
5' cap
poly-A tail
splicing of introns
What are the three types of passive transport discussed in class?
diffusion, facilitated diffusion, and osmosis
What is the extracellular matrix made up of and what is it's purpose?
ground substance + protein fibers; gives connective tissue its function
What is the ratio of neurons to neuroglia?
1:10
What is chromatin?
DNA in the nucleus that is wrapped around a protein called histones. Can be loosely wrapped (euchromatin) or tightly wrapped (heterochromatin)
What important process occurs during the S phase of the cell cycle?
DNA replication
What is denaturation of a protein?
The disruption of protein structure causing proteins to lose their structure usually due to temperature, pH or chemical imbalance
Mast cells release _________ that triggers inflammation
histamine
The umbilical cord has ________ connective tissue that is not present in adults
mucous